Remove ProcessOptions and make the options named arguments.

tests/standalone/io/process_invalid_arguments_test.dart

Index: tests/standalone/io/process_invalid_arguments_test.dart
diff --git a/tests/standalone/io/process_invalid_arguments_test.dart b/tests/standalone/io/process_invalid_arguments_test.dart
index 8dc60d13273cb8f5dddaed6866e9b7f52a726147..bbbc6318bf636e7afd92e2378ab8a1ebddee2f03 100644
--- a/tests/standalone/io/process_invalid_arguments_test.dart
+++ b/tests/standalone/io/process_invalid_arguments_test.dart
@@ -14,24 +14,15 @@ void main() {
                 (e) => e is ArgumentError);
   Expect.throws(() => Process.start("true", ["asdf", 1]),
                 (e) => e is ArgumentError);
-  Expect.throws(() => Process.run(["true"], [], null),
+;
+  Expect.throws(() => Process.start("true", [], workingDirectory: 23),
                 (e) => e is ArgumentError);
-  Expect.throws(() => Process.run("true", "asdf", null),
-                (e) => e is ArgumentError);
-  Expect.throws(() => Process.run("true", ["asdf", 1], null),
-                (e) => e is ArgumentError);
-  var options = new ProcessOptions();
-  options.workingDirectory = 23;
-  Expect.throws(() => Process.start("true", [], options),
-                (e) => e is ArgumentError);
-  Expect.throws(() => Process.run("true", [], options),
-                (e) => e is ArgumentError);
-  options = new ProcessOptions();
-  options.stdoutEncoding = 23;
-  Expect.throws(() => Process.run("true", [], options),
-                (e) => e is ArgumentError);
-  options = new ProcessOptions();
-  options.stderrEncoding = 23;
-  Expect.throws(() => Process.run("true", [], options),
+  Expect.throws(() => Process.run("true", [], workingDirectory: 23),
                 (e) => e is ArgumentError);
+
+  Process.run("true", [], stdoutEncoding: 23)
+      .then((_) => Expect.fail("expected error"), onError: (_) {});
+
+  Process.run("true", [], stderrEncoding: 23)
+      .then((_) => Expect.fail("expected error"), onError: (_) {});
 }